Allen, 22, led all rookie goaltenders this past season with nine wins (9-4-0) and a 2.46 goals-against average. He ranked second among rookies with a .905 save percentage.
The 6-foot-2, 195-pound goaltender posted the best winning percentage (.692) for a Blues rookie in franchise history (at least 10 games) while he became the first rookie since Curtis Joseph in 1989-90 to record at least nine wins.
In addition, Allen dressed in 35 games with the American Hockey League’s Peoria Rivermen, posting a 13-19-2 record along with a 2.89 goals against average and a .904 save percentage.
The Fredericton, New Brunswick native was drafted by the Blues in the second round, 34th overall, in the 2008 NHL Draft.